Overview

Now on Horz surcfaceOnly force isfrictionShould be negative,we're slowing down-1 Incorrect Model (hoizontal)-1 Positive Acceleration-1 Wrong Net Force-1 Wrong Final AnwserBAD HANDWRITTINGNo labels, wrong directionWe're doing the pushing-2pts, forgot person force-1pt, not mentioning more distance horizontal, means less steep angle
  • The mistakes on the test were very avoidable had you drawn a diagram, that's the one thing you should always do. Draw a good diagram. Costed 10 points directly, and at least another 5 indirectly
    We're covering easily the most useful topic in this course IMO: Energy.
  • What is Energy?
  • What kinds are there?
  • What can it do? Energy Problems vs Force problems

Notes

What is Energy

  • The source of ~something~.
  • The source that drives the movement of something
  • Related to force somehow
    - Hypothesis; You get more energy with more force
  • Power cord has energy in it
  • Humza has energy in him
    - Where is the energy in Humza?? SUGAR
    Fuel is energy because it makes cars drive. To make it make cars move, you light it on fire.
    Something has energy in it, if it can make something move.
Definition (Energy).

A property of a system, that with some system can make something move.

  • that means that things with constant velocity might not have net-force, but they do have energy!
Stored Energy (Potential Energy) Moving Energy (Kinetic Energy) Thermal Energy
Moves our cars, powers cities, our phones

To lift up a block to a certain height, we literally move it upward

The force of a spring

Exercise (Given a spring constant of , a mass of , , and a height , how much do I deform the spring to lift the mass).
ENERGY IS CONSERVED

Contents

What about Friction?

What kind of energy does friction make.
FRICTION WILL ALWAYS PRODUCE THERMAL ENERGY

AppleAppleCant move, same network
Homework Total length ~ [60-70min]
  1. Video of balloon compressing when super cold
  2. Demo of conservation of energy with Pendulums and Springs
    1. Spend 5 minutes playing around with this to have your head wrapped around the concept
  3. Demo of energy with a *cool skater guy*
  4. Read Openstax Chapter 7 (30min)
    1. Problems 1-7
  5. Read Khanacamemy's articles on Work and Energy (20min)
    1. Watch this video from them as well. If you like their videos over the articles, then take notes on the respective videos as well, they're identical!
  6. Read a bit of Chapter 6 from the Gioncoli Textbook, skimming is good context
    1. Question 12,13,17,18 Page 162
  7. Do the below exercise
Exercise (Devise a procedure for finding the spring constant of a pen, given the mass of the pen, the "click distance" (how much you push it down to click ), and the height it jumps.).

You have a meter-stick and a phone camera as well. Give a derivation for the spring constant, along with a procedure someone else can follow. Make sure to repeat trials.